Soil-cement bricks produced from local clay brick waste and soft sludge from fiber cement production

Abstract

Soil-cement bricks were produced using local clay brick waste (CBW) and soft sludge (SS) from fiber-cement industries, preserving raw resources by substituting with industrial wastes. The control formula to produce soil-cement bricks, is 15 wt% Portland cement, 15 wt% sand, and 70 wt% laterite. Clay brick waste was added with values from 10 to 50 % of laterite weight in the control formula. For SS, 5 and 10 % was used to replace the total weight of the dry mixture in the control formula. The samples were shaped by using a manual brick making machine. The results showed that the compressive strength of all by-product bricks exceeded industry standards. The maximum compressive strength was attained for 10 % replacement of laterite by CBW. When using both SS and CBW, thermal conductivity and weight of the bricks were further reduced. However, the percentage of water absorption incorporated into the by-product bricks was higher than that of the control formula but still within permissible limit of the industrial standard for load-bearing applications. All by-product bricks showed lower thermal conductivity compared with the control formula. Soil-cement bricks produced with industry by-products have improved or provided similar properties to control formula soil-cement bricks. The utilization of CBW and SS content in the brick samples can save natural resources, decreasing fuel consumption, and reduce CO2 emissions during delivery.

Keywords

• Clay brick waste
• Soft sludge
• Soil-cement bricks
• Thermal conductivity
• Recycling
• Circular economy